Can SMS interventions increase vaccination? Evidence from the COVID-19 pandemic in Kenya
Journal of Development Economics · 2025 · Kevin Carney、Leah R. Rosenzweig、Wendy Wong、Florence Akech、James R. Otieno、Elisa M. Maffioli
中文摘要
研究人员、实践者和政策制定者通常将短信服务（SMS）干预视为影响个人决策的快捷且成本低廉的工具。在很大一部分人口居住于偏远地区、但移动电话技术日益普及的国家，短信尤其具有吸引力。我们与肯尼亚卫生部合作，发送了一系列包含行为助推和经济激励的短信，以鼓励逾期未接种第二剂 COVID-19 疫苗的人完成两剂基础免疫程序。运用行为经济学原理，我们在 2022 年 7 月至 2023 年 1 月期间开展了四项实验，随机向 51,903 人发送短信，鼓励他们完成疫苗接种。我们没有发现这些旨在助推行为或提供经济激励的短信显著提高疫苗接种完成率的证据。对 105 名受访者子样本进行的后续电话调查显示，尽管 91% 的人记得收到过短信，但 84% 的样本表示对该病毒并不担忧或仅有一点担忧。我们的数据表明，尽管接收者记得那条特定短信，但仅发送一条内容显著性较低的信息，可能无法有效改善健康结果。
Abstract
Researchers, practitioners, and policymakers often view Short Messaging Service (SMS) interventions as quick and inexpensive tools to influence individual decisions. SMS text messaging is particularly attractive in countries where much of the population lives in remote areas but mobile phone technology is becoming increasingly widespread. In partnership with the Ministry of Health in Kenya, we sent a series of SMS messages—incorporating behavioral nudges and financial incentives—to encourage individuals overdue for their second COVID-19 vaccine dose to complete their two-dose primary series. Applying principles from behavioral economics, we conducted four experiments between July 2022 and January 2023, sending randomized SMS messages to 51,903 individuals encouraging them to complete their vaccination. We found no evidence that these messages, designed to nudge behavior or offer financial incentives, significantly increased vaccination completion rates. A follow-up phone survey with a subsample of 105 respondents revealed that, while 91% of people remembered receiving the message, 84% of the sample reported being either not worried or only a little worried about the virus. Our data suggest that, despite recipients recalling the specific SMS, a single message with less salient content may not be effective in improving health outcomes.